1. Field of the Invention
The present invention relates to the Internet and the Public Switched Telephone Network (PSTN); and more specifically to the integration of the Internet with the PSTN in such manner that systems, services, and devices on either can communicate with systems, services, and devices on the other, whereby the full benefit and unique characteristics of either network become available to these communications.
2. Description of the Prior Art
The Internet and the PSTN constitute discrete, independent networks from an architectural and operational perspective. Much is written about both networks, especially in terms of their architecture and operation. Consequently, the specification provided herein does not reconstruct that information other than providing general background information. The term xe2x80x9cInternetxe2x80x9d is commonly understood and used throughout the specification and claims in a conventional way. The Internet, in general, is an assemblage of interconnected routers that provide data transport services for server computers and user devicesxe2x80x94typically PCs. The interconnection between routers is provided by private line data circuits, the main lines of which constitute the Internet xe2x80x9cbackbonexe2x80x9d. Internet Service Providers (ISPs) provide access to the Internet via dial up telephone lines with modems, and via dedicated arrangements such as Txe2x88x921 circuits, cable modems on cable-TV systems, and DSL (Digital Subscriber Line) service.
The Internet is designed according to the Internet Protocol (IP), which provides detailed specifications for the construction, addressing, and routing of data packets (occasionally referred to as xe2x80x9cmessagesxe2x80x9d in this document). (The term xe2x80x9cInternet Protocolxe2x80x9d also is used loosely to refer to dozens of related protocols that are used in the Internet.) IP addresses are expressed as a series of digits separated by xe2x80x9cdotsxe2x80x9d (periods), in the form XXX.XXX.XXX.XXX where XXX can be a number from 0 to 255. IP addresses provide a similar function on the Internet as telephone numbers provide on the PSTN. A communication with an Internet device can be established by sending a message addressed to the IP address of that device. Every device capable of communicating on the Internet has an IP address assigned to it, either permanently, or dynamically as needed. IP addresses in some environments are replaced with a proxy address; for purposes of this document, the term xe2x80x9cIP addressxe2x80x9d shall refer to an actual IP address, or a proxy or other identifier translatable into an actual IP address. In some arrangements proxies or agents act on behalf of a client system and substitute the proxy""s IP addresses for the addresses of the client devicesxe2x80x94in these arrangements the combination of the proxy address and the original client system address resolve to provide a unique IP address for each client system. Internet data packets contain the IP address of both the sending system and receiving system (the source and destination, respectively). Since IP messages always contain the IP addresses of both the sending and destination device, when a device receives an Internet message from a sending device, it will then possess the IP address of the sender and can send messages in reply. The two devices can then engage in a communication across the Internet since each has the IP address of the other.
Routers have internal tables that provide routing instructions, which relate IP addresses to the available data circuits and access lines. A router functions by reading the destination address in a data packet, and then forwarding the data packet on one of its data circuits or access lines according to the rules of the routing tables. A data packet gets forwarded from one router to another, pinballing its way across the Internet until it reaches a router that is connected to the destination system.
The term xe2x80x9cPublic Switched Telephone Networkxe2x80x9d, or PSTN, as used herein means the national and international telephone network, actuated when a user dials a telephone number associated with any other phone, causes it to ring, and if answered, is enabled to carry on a voice communication (or, more properly, a xe2x80x9cvoice gradexe2x80x9d communication) with the person (or system) at the remote location. Just as the Internet is comprised of an aggregation of interconnected routers, the PSTN is comprised of an aggregation of interconnected local and long distance telephone switching systems. The local switching systems, referred to as telephone company (telco) central offices (CO), provide telephone subscriber services in a geographic area.
As used herein, the term xe2x80x9ctelephone central office switching systemxe2x80x9d refers generically to a class of systems, typically owned by the operating telephone company in any given area, which provide xe2x80x9clocalxe2x80x9d telephony services to telephone subscribers in that area. Generally, the operating telephone company provides the xe2x80x9clocal loopxe2x80x9d cabling and wiring from its central office to the physical location of each of its subscribers (a xe2x80x9ctelephone circuitxe2x80x9d, or a xe2x80x9clinexe2x80x9d). A telephone central office might house several switching systems of this class, each serving up to 100,000 subscribers or more. The central office represents the hub of a wheel having thousands of spokes, each spoke being a physical pair of wires providing telephone service to a subscriber in that area. Subscribers in any given area are provided service by the central office situated in the center of the area. Outside that area the wires home to other similarly situated central offices. The telephone company connects the telephone circuit of a subscriber to an access connection on the switching system, and assigns a telephone number to that circuit. In operation, the switching system (or just xe2x80x9cswitchxe2x80x9d) provides battery voltage on the phone line, sends dial tone to the subscriber line when the subscriber""s phone goes off hook, receives the dialed digits, and then routes the call according to its internal instructions based on the called number.
Common manufactured switching systems of this class include the Lucent Technologies 5ESS, and the Nortel DMS 100. All telephone central office-switching systems around the world are interconnected by xe2x80x9ctrunkxe2x80x9d circuits that carry voice or voice grade telephone calls between systems, and most (if not all) such systems are also interconnected by a messaging network referred to as CCS/SS7 (Common Control System/Signaling System 7), or just SS7. Long distance calls to telephones outside of the area served by the local telephone company are typically routed to a long distance carrier, such as ATandT, MCI, or Sprint in the USA. The telephone central office switches connect via trunking and messaging circuits to a class of switching system referred to as a xe2x80x9ctoll switchxe2x80x9d, such as the Lucent Technologies 4ESS, operated by a long distance carrier. Toll switches normally do not provide local telephone services.
In the current state of the art there are two inter-related messaging systems utilized within the PSTN. These are: (i) SS7; and (ii) ISDN (Integrated Services Digital Network), which incorporates a messaging system as an element of a broader product and service architecture. The SS7 messaging system extends through the major elements and systems of the PSTN, connecting virtually all of the local and long distance central offices, and carries call management (or call control) messages relating to call setup and disconnection and similar call management functions. Whereas the SS7 messaging system is oriented toward providing messaging communications among and between the PSTN switching systems, the ISDN messaging system is oriented toward extending the PSTN messaging system to the end devices such as telephones and office telephone systems. Rather than going off hook and drawing dial tone from the local central office switching system to initiate a call, as analog phones do, an ISDN phone sends a packetized digital call setup message to the switching system to initiate a call. Both the ISDN messaging system and the SS7 messaging system are based on the X.25/X.75 communications protocols. ISDN messages are carried on the SS7 messaging network. Disadvantageously, neither the SS7 nor the ISDN messaging systems carry any messages related to creating an Internet communication by one device dialing the telephone number of another.
The ISDN and SS7 messaging systems are call setup and call management (or call control) systems which carry a spectrum of messages, message responses, message acknowledgements, and the like, such as are necessary to conduct telecommunications. A full listing of all the message types that might be employed in a robust telecommunications environment has not been attempted herein, since that depth of information is not necessary to convey the essential elements of this invention. A brief listing of those message types include: (i) call setup request messages which convey dialing and associated information; (ii) busy signal messages telling the calling device to deliver a busy signal to the user; (iii) audible ring back messages telling the calling device to deliver xe2x80x9cpacifierxe2x80x9d ringing to the user; (iv) call request acceptance or rejection messages (v) call connect messages; (vi) call disconnect messages; (vii) switchhook flash messages; (viii) call transfer request messages; (ix) call conference messages; (x) call waiting messages; (xi) Caller-ID and Call Waiting-ID messages; and (xii) call forwarding messages to redirect a call to another device. In addition to these messages, a variety of other messages would be employed to indicate information like xe2x80x9cnetwork busyxe2x80x9d, xe2x80x9cinvalid telephone number dialedxe2x80x9d, and the like.
Conventional communication vehicles comprise computers and telephones. Computers typically have telephone lines attached to them, and telephones oftentimes have computers attached to them; but there is no true integration that enables the blending of the Internet and the PSTN. The level of integration that is presently attained permits a computer to use a phone line to dial into the Internet. Once on the Internet, the computer can access another computer by entering its Internet Protocol (IP) address into application software such as a browser.
In an associated matter, there are now a variety of technologies that provide both Internet and PSTN connectivity. These technologies include: (i) Voice over IP (ii) DSL service; (iii) cable modem service delivered by cable-TV systems; (iv) fixed wireless systems; and (v) Internet capable cellular wireless systems.
In one aspect, the systems described herein relate to Voice over IP service. The term IP refers to the xe2x80x9cInternet Protocolxe2x80x9d, the basic protocol of the Internet, while the term Voice over IP refers to sending digitized voice across the Internet using the IP protocol. Several companies provide discount rate phone calls using xe2x80x9cVoice over IPxe2x80x9d (VoIP) technology, wherein a long distance call of a client, typically a Personal Computer (PC) user, is carried over the Internet to a VoIP interface device in the vicinity of the called party. Such VoIP technology avoids the charges associated with placing a long distance call with a traditional long distance carrier. The VoIP interface device dials a local call on the PSTN to complete the connection for the VoIP client. Hence, the call travels partially over the Internet and partially over the PSTN as an analog call. A VoIP software application at the client device digitizes the user""s voice and sends that as data messages across the Internet to the VoIP interface device. The VoIP interface device in turn converts the data messages to analog signals that are output onto the analog phone line. In the reverse direction, the VoIP interface device receives analog signals from the dialed phone and converts those analog signals to digital messages, which it sends across the Internet to the VoIP client. The VoIP software at the client converts those digital messages to analog signals, which are output to the user via speakers.
As background information, there are a group of standards and draft standards from the ITU (International Telecommunications Union) and the IETF (Internet Engineering Task Force) relating to Internet telephony. These standards include H.323, H.245, and T.120, and collectively define how Internet phones should work, including such matters as call connection, determining the capabilities of the receiving phone, conferencing, transferring files and images, enabling shared whiteboards, audio and video codecs, supported transport protocols, etc. These standards do not specify arrangements for integrating the Internet with the PSTN as are provided for by the inventions of this patent application.
In another aspect, the systems described herein relate to an Internet access technology currently being deployed that is referred to as DSL (Digital Subscriber Line) service. (The original acronym was ADSL, for Asynchronous Digital Subscriber Line.) Although there are some variations on the technology (now generically referred to as xe2x80x9cxDSLxe2x80x9d), it essentially involves an analog telephone line supplemented by a high frequency carrier signal superimposed on the telephone line by a pair of modemsxe2x80x94one at the subscriber location, and one at the telephone company central office. The DSL carrier signal can carry high-speed data concurrently over the same phone line without interfering with the analog phone service. Other than being carried by the same physical wires, the phone line has no relationship to the DSL Internet service.
In another instance, the matter to be discussed relates to virtual phone service provided via cable TV. Cable TV service has been used to provide high-speed Internet accessxe2x80x94the popular xe2x80x9ccable modemxe2x80x9d service. In addition, there are a number of current activities related to delivering alternative provider telephone service via the cable TV distribution system. Similar to the Internet access service arrangement, the telephony service arrangement utilizes a xe2x80x9ccable modemxe2x80x9d to transmit and receive voice grade telephone calls. Other than being carried by the same physical cable, telephone service provided by cable TV has no relationship to the cable modem Internet service.
A related matter is that of virtual phone service provided by the so-called fixed wireless arrangement, currently undergoing field trials in some areas, and by the newly introduced cellular telephone service with Internet access. Although these are substantially different services from a user perspective, the wireless infrastructure is much the same.
In each of these technologies, even though they provide both Internet and PSTN connectivity, the Internet aspect is separated from the telephony aspect. Furthermore, none of these technologies enables one device to create an Internet communication with another device simply by dialing its telephone number.
Although they are discrete, independent networks, the Internet and the PSTN touch each other at the edges, in two fashions.
A.) Referring to FIG. 1, most computer users access the Internet 10 using a phone line 16, modem 17, and phone 18 connected to their Personal Computer (PC) 20 by dialing into a phone number provided by an Internet Service Provider (ISP). The phone lines 21 for these numbers are connected to devices called Terminal Servers 22, which incorporate compatible modems and concentrate the circuitry for multiple phone lines and modems. The Terminal Server has a high-speed digital connection 24 to the Internet, commonly in the form of a Txe2x88x921 circuit, which is shared by all dial-in users (the concentrator function). The Terminal Servers are typically located in a telephone company central office 12, but owned by an ISP. The main component of the telephone company (telco) central office (C.O.) is a telephone switching system 14. The C.O.""s are connected together via communications links 26, and the aggregate of C.O.""s, switching systems, and interconnection links collectively constitutes the PSTN 28.
ISP""s are in the business of providing Internet connectivity to subscribers of their service for a monthly fee or similar type of reimbursement (some ISP""s use an advertising supported scheme, nevertheless, they are compensated for their service). Once a subscriber such as that shown as computer A dials in to and establishes a connection with ISPI at the Terminal Server 22, a logical connection is created using the Internet protocols which allows the user to communicate with available systems on the Internet. Such a communication is initiated by the user sending a data message to the IP address of another system on the Internet.
B.) Several companies are in the business of providing discount rate phone calls using a technology called xe2x80x9cVoice over IPxe2x80x9d (VoIP), in which a long distance call is carried over the Internet to a drop off point in the vicinity of the called party. At the drop-off point there is a Terminal Server 22 type of device, working in reverse, such as that shown in FIG. 1 for Voice over IP carrier 1 (VoIP1). As before, this device has a high speed shared connection to the Internet 24, and has multiple local telephone lines 21 connected to it. Since the purpose of this device is to allow Internet users to make voice telephone calls, it would not normally have modems connected to the local telephone lines 21. Operationally, multiple, concurrent voice sessions are carried digitally over access connection 24 (multiplexed), and are distributed or demultiplexed to individual telephone lines 21. To distinguish this type of device from a standard Terminal Server, we will refer to it as a Voice over IP distribution device.
The Voice over IP carrier provides each of its users with a software application (not shown) that enables the computer user to enter a number to be dialed. The computer user A, having created an Internet connection as described previously, dials a phone number by using the VoIP software application. That software application, perhaps operating in conjunction with other systems of the VoIP carrier, creates a logical connection across the Internet to a remote VoIP distribution device such as that labeled VoIP1. Upon receiving a request from a user to create a telephone connection, the VoIP distribution device takes a local phone line 21 off hook and dials the number input by user A. When the remote party answers, perhaps someone at the phone labeled B, a voice connection (or xe2x80x9cvoice gradexe2x80x9d connection) is established. The business proposition for VoIP is that ISP""s charge either a flat rate or an hourly rate for usage, but once a user""s data gets on the Internet, it can go anywhere in the world for no additional fee. The ISP""s fee is small compared to the per-minute charges of telephone companies, and there is no charge equivalent to the telephone companies"" long distance charge. Since the long distance component is free, and the monthly ISP subscription fee has already been paid by the subscriber, the VoIP carrier only has to bill enough to recover the costs of providing the VoIP distribution devices and local phone lines.
What is not provided by either of these two arrangements is a mechanism by which a user either on or off the Internet can dial a phone number and, if the device associated with that phone number has Internet connectivity, communicate with that device via the Internet. If such an arrangement were possible, then those two devices could communicate with all the richness that the Internet has become known for, by simply by dialing a phone call. Because of the voids in current technology, there remains a need in the art for a method and means to integrate the Internet with the PSTN.
The present invention provides a method and means for integrating the Internet with the PSTN such that an Internet communication can be created by one device calling the telephone number of another. In accordance with the invention, devices for integrating the Internet with the PSTN (xe2x80x9cIntegrated Devicesxe2x80x9d) have an Internet connection with an associated IP address, and have a telephone connection with an associated telephone number. The telephone connection to the PSTN could be a virtual telephone line, such as that being provided over cable-TV systems.
In order to conduct an Internet conversation between two devices, each device must have an IP address. This invention provides for a means to obtain the IP address of at least one of the calling and called devices and to provide that IP address to the other, such that one of the two devices can initiate a communication to the other over the Internet. The Internet Protocol incorporates the IP address of the sender and the receiver in every message. When one device initiates an Internet communication to the other, the receiver automatically learns the IP address of the sender and a two-way communication can commence.
There are a variety of ways to obtain the IP address of a calling or called device. In each such arrangement, there are provided telephone number cross-references which contain the IP address associated with the telephone number of an Integrated Device. In simple terms, Internet devices or telephone devices wishing to communicate with an Integrated Device known by a telephone number can determine if that telephone number has an IP address associated with it by looking it up in a cross-reference, or by having an agent such as a telephone central office perform that lookup. Cross-references of IP addresses to telephone numbers could be maintained in the Internet, in the PSTN, in the device, or in any combination of the three.
Once an IP address has been obtained for a calling or called device it must be delivered to the other device. This invention also provides a means for delivering the IP address of one device to the other. In general terms, this requires an addressable digital messaging arrangement such that digital messages can be sent to one or the other of the two devices. The Internet, of course, satisfies this requirement and is suitable in some scenarios, such as that illustrated in FIGS. 2, 3, and 5. However, there also are other available technologies suitable for sending addressable digital messages in a telecommunications environment, such as the messaging component of ISDN service (Integrated Services Digital Network). This aspect of the invention inherently requires that the sender know the digital address of the device to which the message will be sent. In some scenarios, that address will be an IP address, perhaps discovered from a cross-reference. In other scenarios, such as an ISDN environment, that address is automatically tied to the telephone number, so one device only needs to know the telephone number of the other to send it an ISDN message. In yet other scenarios, the telco switching system will know that address from subscriber records.
The Internet already maintains a cross-reference system, referred to as the Domain Name Service (DNS), which allows an Internet xe2x80x9csitexe2x80x9d or xe2x80x9clocationxe2x80x9d to be publicly known by an alphanumeric name, such as Sears.com or Toyota.com, rather than by the strictly numerical IP address. (A master registry is maintained by the InterNIC organization, and is copied daily to thousands of DNS servers around the world.) This DNS service could be expanded to also maintain telephone numbers for these Internet locations. In addition, the cross-reference of IP addresses to telephone numbers could be indirect via the use of names by looking up a telephone number (TN) to find a name, then looking up the name to find the IP address. In the more straightforward version of this arrangement, if an Internet device wished to communicate via the Internet to a device known by a telephone number, it could query an appropriate DNS server for the telephone number. If the called device is listed in the DNS server as having an IP address, the calling device will receive that information back from the query. The calling device may then communicate with the called device via the Internet.
In another cross-reference version, the Integrated Devices themselves could provide the cross-reference of telephone number to IP address by a device knowing its own TN and IP numbers. The calling and called devices could exchange this information using available techniques such as the messaging system incorporated into ISDN.
The PSTN could also maintain a cross-reference of telephone numbers having associated IP addresses. Thus, if a device, having an IP address, called a second device, also having an IP address, and the PSTN maintained a cross-reference of these numbers, then the PSTN could notify the caller of the called device""s IP address via some appropriate means (or optionally, notify the called device of the caller""s IP address). The caller could then communicate directly with the called device via the Internet. In the discussions of the PSTN, it should be understood that the PSTN is no more a monolithic whole than is the Internet. It is comprised of very many telephone companies and authorities, and each might have very many switching centers (telephone company Central Offices). Therefore, in an arrangement in which xe2x80x9cthe PSTNxe2x80x9d maintains a cross-reference between phone numbers and IP addresses, it would be reasonably understood that an authority, company, regional district, or Central Office might maintain such a cross-reference for local subscribers, and depend on other authorities, companies, regional districts, or Central Offices to maintain the same information for their own local subscribers.
There are several possible ways for the PSTN to notify the calling device of the remote device""s IP address. The worldwide PSTN has a messaging system interconnecting all the major switching centers (known as Call Control System/Switching System 7, or CCS/SS7, or just SS7). It would be reasonable to anticipate that telephone companies might use SS7 for this purpose by forwarding an IP/phone number query to the serving agency of the called device via SS7, and receiving the query response and IP address by SS7. As another possibility, the PSTN might use an existing messaging technology such as the digital messaging capability incorporated into the Integrated Services Digital Network (ISDN), or Analog Display Screen Interface (ADSI). As still another possibility, the PSTN might have Internet access in order to communicate with the calling device via an Internet message. Since multiple workable arrangements are possible, we only need to specify that if the PSTN maintains an IP/telephone number cross reference, it must have a method of sending appropriate messages to one or the other or both of the calling and called devices.
In any of the above cross-referencing arrangements, the resulting xe2x80x9ccommunicationxe2x80x9d between the devices could be entirely over the Internet (voice, screens, images, etc.), or part of the communication could transpire over the Internet (the screens and images, for example), and part could transpire over the PSTN (the voice communication, for example).
Using the inventions and arrangements outlined herein, a suitably equipped telephone user or Internet user wishing to communicate with a suitably equipped device known by its telephone number could create an Internet communication with that device. Moreover, an individual Integrated Device telephone could be reached either via the PSTN by dialing the phone number, or via the Internet by using an Internet addressing scheme. The phone number can be dialed from any phone or Integrated Device on the PSTN, or from any VoIP enabled device on the Internet.